In The Great Gatsby, in which places do the most important events occur?

First, the most important events need to be identified and that list depends on the depth of the level of importance.  A few important events and their locations follow:  Nick and Jay meeting for the first time is an important event because it helps to establish Nick's opinion of Jay.  That occurred at Jay's house.  Tom and Daisy meeting one another again for the first time in five years is important and that occurred at Nick's house.  The emotionally explosive scene that occurred in a hotel in New York City where the truth about Jay's and Daisy's relationship comes out and the truth comes out about how Daisy feels about Jay is a major scene.  Daisy hits and kills Myrtle in front of the Wilson's garage in the valley of ashes.  George Wilson kills Jay at Jay's mansion.  Other events that I would rate of slightly less importance are Nick's introduction to Jordan which occurred at Daisy's and Tom's mansion. Nick's introduction to Myrtle occurred at the Wilson garage in the valley of ashes but his glimpse into the affair between Tom and Myrtle took place in New York City which is also where Nick met Meyer Wolfshiem.  Looking into Jay's past, then an important event was his meeting Dan Cody which took place on the shores of Lake Superior and Jay's meeting Daisy which took place at her house in Louisville, KY.